Vehicle headlight



Sept. 8, 1964 R. w. JOHNSON VEHICLE HEADLIGHT 2 Sheets-Sheet 1 FiledJune 3, 1960 INVENTOR. Rov W. JOHNSON BY $14; 64V-4L M ATTORNEYS P 1954R. w. J-OHNSON 3,148,301

VEHICLE HEADLIGHT Filed June 5, 1960 2 Sheets-Sheet 2 i F E 92 FIG. 4(78 no. 5

INV EN TOR. Rov W. JOHNSON ATTORNEYS United States Patent 3,148,391VEHECLE HEADLIGHT Roy VJ. .lohnson, 794 Trombley, Grosse Pointe Park,Mich. Filed June 3, 19643, Ser. No. 33,739 1 Gairn. (ill. 313-11 Thisinvention relates to a vehicle headlight and more particularly to aheadlight of the type which is adapted to project either a high ordriving beam, as it is sometimes called, or a low or passing beam.

It is well known and understood that the most efficient design of aheadlight reflector is parabolic. With a parabolic reflector and afilament located at the focal point of the reflector, the light raysreflected are directed generally parallel to the central axis of thereflector. A minimum of scattering and diffusion results from reflectorsof this design when the light producing filament is concentrated at thefocal point of the reflector. In the case of headlights requiring bothhigh beam and low beam filaments, it is obvious that both filamentscannot be located at the focal point of the reflector. Thus, a problemis presented with respect to the design of a headlight reflector havingboth high and low beam filaments.

Various approaches towards a solution of this problem have beenattempted in the past. In some cases, the two filaments are spaced apartbut located as close as practically possible to the focal point of thereflector. With such location of each filament, neither is capable ofproducing the most efficient reflection. In other cases, one of thefilaments is located at the focal point and the other filament closelyadjacent. With the latter arrangement, inefiicient lighting results withat least one of the filaments. Still another approach has been in theuse of a reflector comprising two parabolidal-shaped portions staggeredaxially relative to one another with a filament placed at the focalpoint of each portion of the reflector and with a third filament locatedbetween the two. This latter type of reflector does not solve theproblem because the light emanating from each filament is reflected byboth portions or" the reflector and there is therefore divergence in thereflected light beam.

It is an object of the present invention to provide a reflector for aheadlight which is designed to produce most efi'icient illumination withrespect to both the driving beam and the passing beam.

A further object of the invention resides in the provision of aheadlight having two parabolidal-shaped reflecting portions with twofilaments, one located at the focal point of each reflector portion andwith a mask or shield disposed between the filaments so that the lightemanating from one of the filaments strikes only one of the reflectorportions and the light emanating from the other filament strikes onlythe other reflector portion.

A further object of the invention resides in the provision of aheadlight which can be manufactured economically and the reflector ofwhich comprises a pair of paraboloidal-shaped portions.

In the drawings:

FIG. 1 is a vertical sectional view of a headlight constructed inaccordance with the present invention.

FIG. 2 is a perspective view of a mask employed between the twofilaments of the headlight.

FIG. 3 is a sectional view taken along the lines 33 in FIG. 1.

FIG. 4 is a diagrammatic showing of the field of illumination producedby the headlight of this invention with the driving beam.

FIG. 5 is a view similar to FIG. 4 showing the field of illuminationwith the passing beam.

Referring to FIG. 1, the headlight of the present in- 3,1483%. Patentedfliept. 8, 1964 vention is illustrated as having a reflector 10 moldedfrom glass or the like and having a central integrally molded base 12from which project the conventional electrical contact prongs 1.4.Prongs 14 are adapted to connect the headlight filaments with thevehicle electrical system. The headlight illustrated is of the sealedbeam type having a lens 16 sealed to the peripheral head 18 around theopen end or" the reflector 10. A glass reflector is shown by way ofillustration, not limitation.

Reflector 10 comprises an upper portion 20 and a lower portion 22 whichare separated by an intermediate spacer portion 24. Portions 2%, 22 and24 are integrally molded as one piece. The upper portion 21 and thelower portion 22 are each formed as a semi-paraboloid. The focal pointof the upper portion 20 is located on its central axis at 26 and thefocal point of the lower portion 22 is located on its central axis at23. In the illustrated arrangement the focal points 26, 23 are shownvertically aligned one above the other. Each of these focal points liesin the horizontal plane forming the junctures between the upper andlower edges 39 and 32, respectively, of the intermediate portion 24 withthe upper portion 20 and the lower portion 22, respectively.

Two light producing filaments designated 34 and 36 are located at thefocal points 26 and 28, respectively. In the arrangement illustrated,the filament 34 is adapted for producing a driving beam and the filament36 is adapted for producing a low beam. Each of these filaments aremounted in position by means of supporting wires 38 and the filamentsare connected with the appropriate prongs 14.

As mentioned previously, the filaments 34, 36 are spaced apartvertically a distance corresponding to the thickness of the intermediateportion 24. Between the filaments 34, 35, there is arranged a mask 4t).Mask it) comprises a generally horizontally disposed central portion 42and upright flange portions 44 at the opposite lateral ends of thecentral portion 42. It will be observed that the upright flange portions4 extend above and below the plane of the central portion 42. Mask isdesigned such that the light emanating from filament 34 is shielded fromthe reflecting surface 46 of the lower portion 22 of the reflector andthe light emanating from the lower filament 36 is shielded from thereflecting surface 48 of the upper portion 2%. Thus, as shown in FIG. 1,the forward edge 59 of mask 49 terminates at a line such that theforwardly directed light rays 52 and 54 emanating from the filaments 34and 36, respectively, which just clear the forward edge 59 of the maskstrike the peripheral edge of the reflector. The rearwardly directedrays 56 and 53 which just clear the rear edge 64 of mask 40 strike theintermediate portion 24 of the reflector. Likewise, as seen in FIG. 3,the laterally directed rays 62 of filament 34 and the laterally directedrays 64 of the filament 36 which just clear the lower and upper edges,respectively, of the upright flanges 44 of mask it) strike theintermediate portion 24 of the reflector. Thus, none of the effectivelight rays of filament 34 strike the reflecting surface 46 of the lowerportion 22 of the reflector and none of the effective light rays fromfilament 36 strike the reflecting surface 48 of the upper portion 20 ofthe reflector. In other words, the light rays from filament are in noway scattered or diffused by the reflecting surface 46 and the lightrays from filament 36 are in no way scattered or diffused by thereflecting surface 48. Thus, each of the filaments 34, 36 is arranged toproduce the most efiicient fighting by limiting the field of theirreflection to their respective reflector portions 48, 46.

While lens 16 could be oval, square or of other shape, it is mosteconomical, of course, to provide a lens 16 which is perfectly circularin contour. Thus, it is desirable that the inner and outer peripheriesof the bead 18 designated 66 and 68, respectively, be likewise circularin contour. The outer periphery 63 is made circular by simply formingthe cavity in the reflector mold of circular shape at the portionthereof corresponding to the peripheral edge 18. The punch used with themold in forming reflector It would be initially formed as twoparaboloidal-shaped portions with an insert corresponding in size tointermediate portion 24 between the two paraboloidal-shaped portions ofthe punch. In order to provide an inner periphery of the reflector as at66 of circular shape, the end of the punch corresponding to theperipheral edge 18 of the reflector is turned down to cylindrical formwhich accounts for the cylindrical surface portions 70 on the upper andlower portions of the reflector. These cylindrical surface portions havea zero axial dimension at the upper and lower edges 39, 32 ofintermediate portion 24 and have their maximum axial dimensions at thetop and bottom of the reflector. In FIG. 3, the broken line 72represents the contour that the punch would have prior to being turneddown to circular shape as indicated at 66.

Lens 16 is shaped on its inner surface with a suitable configuration asshown at 74 for producing the desired pattern and direction of the beam.Desirable patterns for the high beam and low beam are illustrated inFIGS. 4 and 5. FIG. 4 shows the light pattern for the high beam ordriving beam, as it is sometimes called, wherein a small but brightlyilluminated area 76 is located in a central portion relative to thevehicle and a less brightly illuminated area 78 extends laterally beyondand below the brightly illuminated area 76. The pattern illustrated inFIG. 4 would be produced by the combination of the filament 34 with thereflecting surface 48 and the proper configuration of the inner surfaceof lens 16'. The passing beam illustrated in FIG. 5 has the small butbrightly illuminated area 80 shifted to the right and surrounded by thelarger less brightly illuminated area 82. The pattern illustrated inFIG. 5 would be produced by the lower filament 36 in combination withthe reflecting portion 46 and the necessary configuration of the innersurface of lens 16.

It will be appreciated that the two halves of the reflector need not bevertically superposed. They could be located side by side instead of oneabove the other. Likewise while it is preferred to have the two focalpoints lying in the same vertical plane, they may be otherwise spacedapart. It is essential however according to the present invention thatthe focal points of the two portions of the reflector be spaced apartand shielded from one another.

I claim:

A headlight for a vehicle comprising a unitary, onepiece reflectorhaving an upper portion, a lower portion and an intermediate portion,said upper and lower portions each having on the inner side thereofidentical reflective surfaces of generally semi-parabolic shape, saidintermediate portion forrning an integral connection between the upperand lower portions and spacing said upper and lower portions uniformlyapart, the inner surface of said intermediate portion being of parabolicshape in horizontal section, said reflective surfaces of the upper andlower portions being vertically spaced such that the focal points ofsaid reflective surfaces are vertically spaced in the same verticalplane, a filament located generally at the focal point of the reflectivesurface of the lower portion, a filament located generally at the focalpoint of the reflective surface of the upper portion, said filamentsbeing spaced vertically apart a distance corresponding generally to thethickness of the intermediate portion, a mask extending between saidfilaments and shielding the rays of the upper filament from thereflective surface of the lower portion and the rays of the lowerfilament from the reflective surface of the upper portion, saidreflector adjacent the open end thereof having a radially enlarged,circumferentially extending head there on, the outer periphery of saidhead defining a circle the axis of which corresponds to the centrallongitudinal axis of the reflector, the inner peripheral edges of saidupper, lower and intermediate portions at the open end of the reflectoralso defining a circle concentric with the firstmentioned circle and alens closing the open end of the reflector, the inner and outerperipheral edges of the lens also being of circular shape, thereflective surfaces of the upper and lower portions of the reflectoreach being fashioned with a cylindrical portion at the open end thereof,said cylindrical surface portions, in view of the semiparabolic shape ofthe upper and lower reflector portions, having a maximum axial dimensionat the vertical central portions of the open end of the reflector andtapering to a substantially zero dimension at the junction of thereflective surfaces of the upper and lower portions with the innersurfaces of the lower and intermediate portions.

References Cited in the file of this patent UNITED STATES PATENTSAstivia July 25, 1961

